Apparatus for making castings.



Fig.1.

H. P. MARSHALL.

APPARATUS FOR MAKING GASTINGS.

APPLICATION FILED DBO. s, 1911.

Patented June 17, 19 13.

2 SHEETS-SHEET l.

H. P. MARSHALL;

APPARATUS r03 MAKING GASTINGS.

APPLICATION FILED DEOJ, 1911.

1,065,326. Patented June 17,1913.

3 SHEETS-SHEET 2.

t UNITED STATES PATE F I E- mm? P. MARSHALL, or GLEN nines, NEW masnm APPARATUS FOR MAKING CASTINGSF T all whom it may concern.

Be it known. that I, HARRY P. MARS ALL,

metal forced into the cavityby air-pressure or ,otherwlse, although of course the inven tion can be used in any place or for any'purpose to which it is adapted and I do not wish to be understood as restricting myself at all in that respect.

Theobjects of this invent-ion are to provide improved means for simultaneously subjecting a mold to the heat of a furnace and exhausting air from it; 'to enable a furnace to be utilized for this purpose which can also be used for other purposes; to provide'a construction for the furnace which shall adapt it to each of said uses without interfering with its other uses; to secure a com act and convenient apparatus, and to obtain other advantages and results as may be brought out in the following description.

Referring to the accompanying'drawings, in which like numerals of reference, indicate the same parts throughout the several figures, Figure 1 is a view in side elevation of an apparatus of my improved construction showing the furnace and supports above the shelf 15 in section; Fig.2 is a plan of the same; Fig. 3 is a front, end view, with the furnace door open, and Fig. 4 is a detail section through the mold ring seat in the floor of the furnace.

In said drawings, 1 indicates a pump having a piston adapted to be operated by the handle 2 to exhaust air through the pipe 3, which pipe in the specific embodiment of the invention shown in the drawings extends upward from the pump 1 and forms the forward support for a furnace 4 above the pump, and which furnace I have shown as an electric furnace containing an electric heating medium 24, although I do not wish to be restricted to that kind alone. The pump 1 has feet 5 and a flattened top 6 55 which receives a plate 7 preferably of in.-

sulating material which has the binding Specification of Letters Patent. PatentedJ 11116 17,1913." Application filed December 5,1911. Serial No. 663,988. i 1

adapted to close against a, ledge convenient and is at posts 8 for the electric Wires 9, a. rheos tat or resistance box 10 and switch .11 forlrna'ni, 'u} lating the same. Fromsthis plateflatu. u-j lar support 12 extends1npwardtothejreai m end of the furnace 4. .-..T.he-- furnace itself is of the usual tubular form with aninteiiior flattened floor, and hasa, door 13 ,vthc

1 tially flush with the said floomas 9 The door has an openingl13ayhic 1m covered by any suitable materialdsuch glass, mica, etc. A shelf gt; 1

upon and connect the lf uraace uppgrts 2 which forms the suctiq is preferably provided. r tween said shelf and a-plae a While the constructiomag a of parts above described s coinpactfaiid meantime preferred construction and arifangemen it.

should be considered onlygasg illustrative dfi various constructions arrangements which could be adapted to mypurphse ,and go I do not wish to be understood-as irestricti myself in this respect exceptgas thee, the art may require orgas positively stated in the cla In the floor 17 of thefur'naee, metal seat 18, which is; integral H forms the top of the uppensection 9311c. P p t bore 0 fish- 1 i mamas through the center of said," at '15,, a in detail in Fig. 4 of- -t he a e-wise, LSeiL 90.: seat 18 provides a-grou'nd surface to receive the correspondingly-ground end of a mold ring 21, so as to form an impervious joint therewith, and to conveniently guide the mold ring into proper position upon said seat, the seat is providedwith a peripheral flange 22. This flange is shown in the drawing as substantially flush at its upper edge with the floor 17, although obviously the relation of said parts might be otherwise if desired.

It will be understood that the mold ring 21 is open at both ends, and that in use it is filled transversely with plaster of Paris or any other known investing substance in which the mold cavity has been formed in any suitable manner, said cavity communicating with a cup-like or hollowed depression in the investing substance at one end of the mold ring, which depression is adapted to receive the material to be melted and run into the mold cavity. In using my improved apparatus, a moldring thus prepared is set firmly upon the seat 18 of the furnace with the hollowed end of the in-' vesting substance containing the material to be cast of course-at the top. The furnace is then heated or brought to the proper temperature to melt the material in the upper end of the mold ring so that it will run or .the material to be cast has become molten in the top of the mold ring, so as to place the mold ring in communication with a partial vacuum, which has been previously produced by pumping, but it will be noted that both material and mold are by my improved apparatus subjected simultaneously to the unbalanced atmospheric pressure and the heat, said heat being uniform and unvaried, even when the molten material flows into the mold cavity. 'As a result, I obtain a certainty of perfect castings, which is of the greatest advantage in saving time, l'abor and material, and furthermore I can make such castings in large sizes and of any material known for such purposes.

A pressure gage 23 is provided for'the vacuum chamber of the pump 1, and any suitable and well-known means can be provided in connection with the furnace for registering the temperatures or degrees of heat attained by it.

It will be noted that the sunken or de-' pressed seat 18 'is located convenient to the door 13 of the furnace so that the mold ring 21' can be conveniently placed thereon, the said seat serving to position the mold ring with respect to'the exhaust duct 20. By this arrangeme 'itlthe furnace is conveniently and advantageously used for casting, and at the same time the mold ring 21 can be removed and the furnace used for any other purpose.-

The.shape and size of the furnace chamber thus makes no difference, since when usedwith the floor of the furnace, said seat adapted to receive a" mold ring inside said flange, a vacuum pump, a duct leading from.

said pump to said seat, and a valve in Said duct. a

2. In an apparatus of the character described, the combination of a vacuum pump having a suitable base, a plate on the top 'of said pump, a suction pipe leading up Ward through said plate from the pump and having at its upper end a seat for a mold ring,'a tubular support on said plate, an

electrical furnace mounted, on said support and pipe with said seat in its chamber, binding posts on said plate, and a valve in said ,pm

3. In an apparatus of the character described, the combination of a furnace, an air exhaust duct opening through the floor of the furnace chamber, and a sunken seat in the floor of the furnace chamber around said air exhaust duct adapted.to receive a'mold and, positionthe same withrespect to said I air exhaust duct.

' HARRY P. MARSHALL.

In the presence of. I a

Coimnnrus ZABmsKm,

FRANCES E. BmDGE'rr. 

